EP2673345B1 - Use of liquid compositions for marking liquid hydrocarbon-based fuels and combustibles, and process for detecting the markers - Google Patents

Description

TECHNICAL AREA

This invention relates to the use of specific chemical compounds as markers for liquid hydrocarbon products or liquid hydrocarbons, such as fuels and liquid hydrocarbon fuels, crude oil. These markers can be used either directly in the hydrocarbon product or via an additive package which is then incorporated into the fuel or fuel.

These markers are intended to mark the liquid hydrocarbon so that it can be quickly identified with respect to its source, its integrity, and in particular that of the additives that are incorporated. When the chemical markers are premixed with one or more additives (commonly referred to in the "additive package" profession) they allow the identification of the type and amount of package incorporated in the liquid hydrocarbon.

PRIOR TECHNIQUES

Many techniques have been used to mark liquid hydrocarbon products for the purpose of identifying their source and integrity, typically involving the incorporation of small amounts of additives or labels into the hydrocarbon.

The detection of the markers can be carried out by a number of standard analytical techniques such as colorimetry, IR, UV or UV-Vis spectroscopy, mass spectrometry, atomic adsorption spectroscopy, gas chromatography and / or liquid chromatography (some of these detection and analysis techniques can possibly be coupled together).

When a liquid hydrocarbon, such as crude oil, a refined petroleum base, a fuel or a fuel containing a marker is accidentally released into the environment, (eg hydrocarbon leaks from bins) storage, service station tanks, pipelines, etc.), the detection of the marker makes it possible to identify the source of the hydrocarbon.
Furthermore, the presence and concentration of the additives incorporated in the fuels to improve their performance can be deduced by measuring the concentration of the added marker either in the fuel or the fuel, or in the additive or the package of additives. . The labeled fuel or hydrocarbon fuel can be controlled anywhere in its distribution network to verify its integrity. This ensures that the fuel or fuel has not been contaminated or diluted with other hydrocarbon liquids; it also makes it possible to verify that there is no under- or overdosing of additives in the fuel or commercial fuel. When a marker is included in the additive package in a given quantity, the concentration of the package in the fuel or hydrocarbon fuel can be deduced by determining the amount of marker in the fuel or final hydrocarbon fuel by implementing a quantitative analysis technique, reliable and precise.

Radioactive markers based on tritium, iodine-131, or sulfur-35 were used to trace crude oil and fuels in pipelines and storage facilities.

For essentially tax reasons, each type of fuel or fuel intended for the general public is additive with a specific marker, called customs tracer, which is in general a particular dye added in a quantity determined by the regulation of the country of marketing.

US 4,141,692 discloses the use of chlorinated hydrocarbons having at least 3 chlorine atoms, at least 2 carbon atoms and a Cl / C atom ratio of at least 1 to 3 as hydrocarbon markers. The detection of these markers is made by an electron capture detector after separation by gas chromatography. The use of chlorinated hydrocarbons as markers of liquid hydrocarbon fuels and fuels has disadvantages, in particular a certain toxicity (release of chlorine gas and / or increase of chlorinated hydrocarbon emissions potentially generating greenhouse gases.)

US4,209,302 describes the use of 1- (4-morpholino) -3- (alpha or beta-naphthylamino) propane at a rate of 0.5 to 12 ppm as a marker of gasoline type fuels. These markers do not color the essence; in order to detect them, it is necessary to carry out a chemical extraction followed by a treatment with diazotised 2-chloro-4-nitroaniline which leads to a solution of pink color, which color can be measured by colorimetry. The major disadvantage of this detection technique is the preliminary chemical extraction step which may lead to increased errors in the measurement.

FR 2 212 390 or US 3,862,120 disclose disazo dyes for water immiscible liquids, especially petroleum fuels and a method for quantitatively detecting their presence in said liquids by IR adsorption or by thin layer chromatography. US 5,234,475 proposes to use as markers of liquid hydrocarbons (gasoline, diesel, jet, ...) one or more fullerenes in amounts ranging from 0.01 to 100 ppm, detectable by mass spectroscopy or by UV-Visible spectroscopy. The manufacture of fullerenes is not currently industrial, these molecules are much too expensive to be incorporated in fuels for convenience to the general public.

EP 512 404 describes the use, as liquid hydrocarbon labels, of chemical compounds having an aromatic ring substituted with 2 NO ₂ groups and a amide or ester group, detectable by gas chromatography. These markers can be incorporated directly into the fuel or via the additive package. These compounds hydrolyze in the presence of traces of water in the hydrocarbon, making their use unreliable for accurate marking and quantitative detection of the fuel.

EP 1 699 907 describes additive packages for fuels or lubricants that include anthraquinone derivatives as markers and the use of these packages in fuels and lubricants.

EP 1 816 181 discloses markers for ethanol fuels which are substituted aromatic compounds, having a ternary axis of symmetry and containing N, O, P, B preferably used between 0.01 ppm and 50 ppm by weight in ethanol fuels.

WO 2010/039152 describes a method of marking fuels for the purpose of authentication, to ensure, for example, their origin and / or any mixtures or dilutions. The chemical nature of the markers is not detailed, it is only stated that the markers may be non-radioactive dyes or isotopes.

US 5,984,983 describes the use of carbonyl compounds as fuel markers. These markers can be chosen from ketones, aldehydes, esters including lactones, amides (including lactams and imides, anhydrides and carboxylic acids, the presence of these markers is detected by the IR absorption of the carbonyl functions. example a gasoline fuel marked with dibutyl phthalate (peak absorbance1740 cm ^-1) and acetophenone (peak absorbance 1700 cm ^-1)

SUMMARY OF THE INVENTION

1. a) au moins un marqueur, choisi parmi les composés aliphatiques ou cycloaliphatiques suivants :
   • ▪ isobutyrate de tricyclodécényle (3a,4,5,6,7,7a-hexahydro-4,7-methano-1 h-inden-5 (ou 6) -yl) ( CAS 67634-20-2 )
   • ▪ propionate de tricyclodécényle ( CAS 17511-60-3 )
   • ▪ acétate de cis 3 hexenyle ( CAS 3681-71-8 )
   • ▪ linalool d'éthyle ( CAS 10339-55-6 )
   • ▪ acétate de prényle ( CAS 1191-16-8 )
   • ▪ myristate d'éthyle ( CAS 124-06-1 )
   • ▪ acétate de para tertio butyl cyclo hexyl ( CAS 32210-23-4 )
   • ▪ acétate de butyle ( CAS 123-86-4 ),
   • ▪ acétate de tricyclodécényle (4,7-méthano-1h-inden-6-ol, 3a,4,5,6,7,7a-hexahydro-)( CAS 5413-60-5 )
   • ▪ caprate d'éthyle ( CAS 110-38-3 )
2. b) un solvant ou un mélange de solvants,
3. c) et éventuellement un ou plusieurs additifs fonctionnels pour carburants et/ou combustibles hydrocarbonés liquides, choisis parmi les détergents, dispersants, améliorants de combustion, anti-mousse, améliorants de conductivité, additifs anti-corrosion, additifs de lubrifiance, agents anti-usure et/ou modificateurs de frottement, agents chélatants et/ou séquestrants de métaux, désémulsifiants, colorants, additifs de tenue à froid, passivateurs de métaux, neutraliseurs d'acidité, marqueurs différents des marqueurs a).

The present invention relates to the use of at least one liquid composition for marking liquid hydrocarbon fuels and fuels in which it is incorporated, said liquid composition comprising:

1. a) at least one marker, chosen from the following aliphatic or cycloaliphatic compounds:
   • ▪ tricyclodecenyl isobutyrate (3a, 4,5,6,7,7a-hexahydro-4,7-methano-1h-inden-5 (or 6) -yl) ( CAS 67634-20-2 )
   • ▪ tricyclodecenyl propionate ( CAS 17511-60-3 )
   • Cis 3 hexenyl acetate ( CAS 3681-71-8 )
   • ▪ ethyl linalool ( CAS 10339-55-6 )
   • ▪ prenyl acetate ( CAS 1191-16-8 )
   • ▪ ethyl myristate ( CAS 124-06-1 )
   • Para-tert-butyl cyclohexyl acetate ( CAS 32210-23-4 )
   • ▪ Butyl acetate ( CAS 123-86-4 )
   • Tricyclodecenyl acetate (4,7-methano-1h-inden-6-ol, 3a, 4,5,6,7,7a-hexahydro-) ( CAS 5413-60-5 )
   • ▪ ethyl caprate ( CAS 110-38-3 )
2. b) a solvent or a mixture of solvents,
3. c) and optionally one or more functional additives for fuels and / or liquid hydrocarbon fuels, chosen from detergents, dispersants, combustion improvers, defoamers, conductivity improvers, anti-corrosion additives, lubricant additives, anti-wear agents and / or friction modifiers, chelating agents and / or metal sequestering agents, demulsifiers, colorants, cold-holding additives, metal passivators, acid neutralizers, markers different from the markers a).

• avoir une stabilité suffisante dans les conditions d'utilisation habituelles de la composition hydrocarbonée liquide,
• maintenir les propriétés physico-chimiques du carburant ou du combustible,
• être compatible avec les composants du package d'additifs et avec ceux du carburant et du combustible
• avoir une stabilité suffisante pour pouvoir être utilisé sous forme de solutions concentrées,
• pouvoir être utilisés en faible quantité et être détectable par des techniques de détection simples, rapides, précises & fiables,
• se distinguer des marqueurs réglementaires et légaux.

The markers a) for liquid hydrocarbon compositions defined above satisfy the following conditions:

• have sufficient stability under the usual conditions of use of the liquid hydrocarbon composition,
• maintain the physico-chemical properties of the fuel or fuel,
• be compatible with the components of the additive package and with those of fuel and fuel
• have sufficient stability to be used as concentrated solutions,
• can be used in small quantities and be detectable by simple, fast, accurate & reliable detection techniques,
• distinguish themselves from regulatory and legal markers.

Advantageously, some of the markers a) defined above have, in addition to the labeling properties mentioned above, additional properties or performances; this is for example the case of 3a, 4,5,6,7,7a-hexahydro-4,7-methano-1h-inden-5 (or 6) -yl isobutyrate, tricyclodecenyl propionate and 4,7 -methano-1h-inden-6-ol, 3a, 4,5,6,7,7a-hexahydro-, acetate which improves the odor and / or bactericidal properties of the fuels and fuels to which they are incorporated, see for example EP 1,591,514 ; butyl acetate and ethyl linalool also have odorous properties, see for example WO 01/363544 and US 2008/096790 .

The marker (s) a) is added in sufficient quantity to ensure detection, and preferably quantification after it has been added to the fuel or fuel. Typically each marker a) is added at a concentration generally ranging from 1 to 500 parts per million by weight (ppm m / m) relative to the total mass of fuel or hydrocarbon liquid fuel additive, and preferably at a concentration ranging from 1 to 50 ppm m / m. Typically, the minimum detection threshold of these markers a) is generally 1 ppm m / m for qualitative detection (ie which makes it possible to identify the presence of marker a) and from 2 to 3 ppm m / m for detection. quantitative.

The (or the solvents) b) in which the marker (s) a) and any other additives c) of the liquid composition are soluble, generally comprises aliphatic and / or aromatic hydrocarbons or hydrocarbon mixtures, for example petrol fractions, kerosene, decane, pentadecane, toluene, xylene, and / or ethylbenzene and / or commercial solvent mixtures such as Solvarex 10, Solvarex LN, Solvent Naphtha, Shellsol AB, Shellsol D, Solvesso 150, Solvesso 150 ND, Solvesso 200, Exxsol, ISOPAR and optionally polar dissolution adjuvants, such as 2-ethylhexanol, decanol, isodecanol and / or isotridecanol.

• ❖ les additifs améliorant de combustion ; pour les carburants de type gazole, on peut citer les additifs procétane, notamment (mais non limitativement) choisis parmi les nitrates d'alkyle, de préférence le nitrate de 2-éthyl hexyle, les peroxydes d'aroyle, de préférence le peroxyde de benzyle, et les peroxydes d'alkyle, de préférence le peroxyde de di ter-butyle; pour les carburants de type essence, on peut citer les additifs améliorant l'indice d'octane; pour les combustibles tels que fioul domestique, fioul lourd, fioul marine, on peut citer le méthylcyclopentadiényl manganèse tricarbonyl (MMT) ;
• ❖ les additifs anti-oxydants, tels que des amines aliphatiques, aromatiques, les phénols encombrés, tels que BHT, BHQ ;
• ❖ les désémulsifiants ;
• ❖ les additifs anti-statiques ou améliorants de conductivité ;
• ❖ les colorants ;
• ❖ les additifs anti-mousse, notamment (mais non limitativement) choisis par exemple parmi les polysiloxanes, les polysiloxanes oxyalkylés, et les amides d'acides gras issus d'huiles végétales ou animales ; des exemples de tels additifs sont donnés dans EP 861 182 , EP 663 000 , EP 736 590 ;
• ❖ les additifs détergents ou dispersants, notamment (mais non limitativement) choisis dans le groupe constitué par les aminés, les succinimides, les succinamides, les alkénylsuccinimides, les polyalkylamines, les polyalkyles polyamines, les polyétheramines, les bases de Mannich; des exemples de tels additifs sont donnés dans EP 938 535 ;
• ❖ les additifs anti-corrosion tels que les sels d'ammonium d'acides carboxyliques ;
• ❖ les agents chélatants et/ou les agents séquestrants de métaux, tels que les triazoles, les disalicylidène alkylène diamines, et notamment le N,N' bis (salicydène)propane diamine ;
• ❖ les additifs de lubrifiance, agents anti-usure et/ou modificateurs de frottement, notamment (mais non limitativement) choisi dans le groupe constitué par les acides gras et leurs dérivés ester ou amide, notamment le monooléate de glycérol, et les dérivés d'acides carboxyliques mono- et polycycliques ; des exemples de tels additifs sont donnés dans les documents suivants: EP 680 506 , EP 860 494 , WO 98/04656 , EP 915 944 , FR2 772 783 , FR 2 772 784 ;
• ❖ les additifs de tenue à froid et notamment les additifs améliorant le point de trouble, notamment (mais non limitativement) choisis dans le groupe constitué par les terpolymères oléfine à chaîne longue/ester (méth)acrylique /maléimide, et les polymères d'esters d'acides fumarique /maléique. Des exemples de tels additifs sont donnés dans EP 71 513 , EP 100 248 , FR 2 528 051 , FR 2 528 051 , FR 2 528 423 , EP1 12 195 , EP 1 727 58 , EP 271 385 , EP 291367 ; les additifs d'anti-sédimentation et/ou dispersants de paraffines notamment (mais non limitativement) choisis dans le groupe constitué par les copolymères acide (méth)acrylique/(méth)acrylate d'alkyle amidifié par une polyamine, les alkénylsuccinimides de polyamine, les dérivés d'acide phtalamique et d'amine grasse à double chaîne ; des résines alkyl phénol/aldéhyde ; des exemples de tels additifs sont donnés dans EP 261 959 , EP593 331 , EP 674 689 , EP 327 423 , EP 512 889 , EP 832 172 ; US 2005/0223631 ; US 5 998 530 ; WO 93/14178 ; les additifs polyfonctionnels d'opérabilité à froid choisis notamment dans le groupe constitué par les polymères à base d'oléfine et de nitrate d'alkényle tels que décrits dans EP 573 490 ;
• ❖ d'autres additifs améliorant la tenue à froid et la filtrabilité (CFI), tels que les copolymères EVA et/ou EVP ;
• ❖ les passivateurs de métaux, tels que les triazoles, les benzotriazoles alkylés ;
• ❖ les neutralisateurs d'acidité tels que les alkylamines cycliques ;
• ❖ d'autres marqueurs que ceux correspondant à la définition des marqueurs a) et notamment les marqueurs imposés par la réglementation, par exemple les colorants spécifiques à chaque type de carburant ou combustible.

In a non-exhaustive manner, the functional additive (s) c) may be chosen from:

• ❖ combustion enhancing additives; for fuels of the diesel type, mention may be made of procetane additives, in particular (but not limited to) selected from alkyl nitrates, preferably 2-ethyl hexyl nitrate, aroyl peroxides, preferably benzyl peroxide, and alkyl peroxides, preferably di-tert-butyl peroxide; for petrol-type fuels, there may be mentioned additives improving the octane number; for fuels such as heating oil, heavy fuel oil, marine fuel, mention may be made of methylcyclopentadienyl manganese tricarbonyl (MMT);
• ❖ anti-oxidant additives, such as aliphatic, aromatic amines, hindered phenols, such as BHT, BHQ;
• ❖ demulsifiers;
• ❖ anti-static additives or conductivity improvers;
• ❖ dyes;
• ❖ anti-foam additives, in particular (but not limited to) chosen, for example, from polysiloxanes, oxyalkylated polysiloxanes, and fatty acid amides derived from vegetable or animal oils; examples of such additives are given in EP 861 182 , EP 663 000 , EP 736 590 ;
• ❖ detergent or dispersant additives, in particular (but not limited to) selected from the group consisting of amines, succinimides, succinamides, alkenylsuccinimides, polyalkylamines, polyalkyl polyamines, polyetheramines, Mannich bases; examples of such additives are given in EP 938 535 ;
• ❖ anti-corrosion additives such as ammonium salts of carboxylic acids;
• ❖ chelating agents and / or metal sequestering agents, such as triazoles, disalicylidene alkylene diamines, and especially N, N 'bis (salicydene) propane diamine;
• ❖ lubricity additives, anti-wear agents and / or friction modifiers, in particular (but not limited to) selected from the group consisting of fatty acids and their ester or amide derivatives, especially glycerol monooleate, and derivatives thereof. mono- and polycyclic carboxylic acids; examples of such additives are given in the following documents: EP 680 506 , EP 860 494 , WO 98/04656 , EP 915 944 , FR2 772 783 , FR 2,772,784 ;
• ❖ cold-holding additives and especially cloud-point-improving additives, in particular (but not limited to) selected from the group consisting of long-chain olefin terpolymers / (meth) acrylic ester / maleimide, and ester polymers of fumaric / maleic acids. Examples of such additives are given in EP 71,513 , EP 100 248 , FR 2 528 051 , FR 2 528 051 , FR 2,528,423 , EP1 12,195 , EP 1 727 58 , EP 271,385 , EP 291367 ; the anti-sedimentation additives and / or paraffin dispersants in particular (but not exclusively) chosen from the group consisting of polyamine-amidated (meth) acrylic acid / alkyl (meth) acrylate copolymers, polyamine alkenylsuccinimides, phthalamic acid and double fatty amine derivatives chain; alkyl phenol / aldehyde resins; examples of such additives are given in EP 261 959 , EP593 331 , EP 674 689 , EP 327 423 , EP 512,889 , EP 832 172 ; US 2005/0223631 ; US 5,998,530 ; WO 93/14178 ; polyfunctional cold operability additives chosen in particular from the group consisting of olefin and alkenyl nitrate polymers as described in EP 573,490 ;
• ❖ other cold-weatherability and filterability (CFI) additives, such as EVA and / or EVP copolymers;
• ❖ metal passivators, such as triazoles, alkylated benzotriazoles;
• ❖ acid neutralizers such as cyclic alkyl amines;
• ❖ other markers than those corresponding to the definition of the markers a) and in particular the markers imposed by the regulation, for example the dyes specific to each type of fuel or fuel.

Functional additives c) are generally added to the liquid hydrocarbon composition (fuel or fuel) in an amount ranging from 5 to 1000 ppm via at least one liquid composition according to the invention and / or incorporated via another additive package and or directly in the hydrocarbon composition.

The liquid hydrocarbon fuels and fuels comprise middle distillates having a boiling point of between 100 and 500 ° C .; their starting crystallization temperature TCC is often greater than or equal to -20 ° C, generally between -15 ° C and + 10 ° C. These distillates are base mixtures which can be chosen, for example, from distillates obtained by the direct distillation of petroleum or crude hydrocarbons, vacuum distillates, hydrotreated distillates, distillates obtained from catalytic cracking and / or hydrocracking. distillates under vacuum, distillates resulting from conversion processes such as ARDS (by atmospheric residue desulfurization) and / or visbreaking.

Liquid fuels and fuels may also contain light cuts such as distillate spirits, catalytic or thermal cracking units, isomerization alkylation units, desulfurization units, steam cracking units.

• les coupes les plus lourdes issues des procédés de craquage et de viscoréduction concentrées en paraffines lourdes, comprenant plus de 18 atomes de carbone,
• les distillats synthétiques issus de la transformation du gaz tels que ceux issus du procédé Fischer Tropsch,
• les distillats synthétiques résultant du traitement de la biomasse d'origine végétale et/ou animale, comme notamment le NexBTL, prise seule ou en mélange. La biomasse végétale ou animale et les huiles végétales ou animales pouvant être hydrotraitées ou hydrodésoxygénées,
• les gazoles de cokeur,
• les alcools, tels que méthanol, éthanol, butanols, les éthers, (MTBE, ETBE, ...) en général utilisés en mélange avec les carburants essence, mais parfois avec des carburants plus lourds de type gazole,
• les huiles végétales et/ou animales et/ou leurs esters, tels que les esters méthyliques ou éthyliques d'huiles végétales (EMHV, EEHV),
• les huiles végétales et/ou animales hydrotraitées et/ou hydrocraquées et/ou hydrodéoxygénées (HDO)
• et/ou encore les biodiesel d'origine animale et/ou végétale.

Liquid fuels and fuels may also contain new sources of distillates, which include:

• the heavier cuts resulting from heavy paraffinic cracking and visbreaking processes comprising more than 18 carbon atoms,
• synthetic distillates resulting from the transformation of the gas such as those resulting from the Fischer Tropsch process,
• synthetic distillates resulting from the treatment of biomass of plant and / or animal origin, such as NexBTL, taken alone or as a mixture. Plant or animal biomass and vegetable or animal oils that can be hydrotreated or hydrodeoxygenated,
• coker gas oils,
• alcohols, such as methanol, ethanol, butanols, ethers (MTBE, ETBE, etc.) generally used in admixture with petrol fuels, but sometimes with heavier fuels of the diesel type,
• vegetable and / or animal oils and / or their esters, such as methyl or ethyl esters of vegetable oils (EMHV, EEHV),
• hydrotreated vegetable oils and / or animal oils and / or hydrocracked and / or hydrodeoxygenated (HDO)
• and / or biodiesel of animal and / or vegetable origin.

These new fuel and fuel bases can be used alone or mixed with conventional petroleum distillates as fuel base and / or fuel; they generally comprise long paraffinic chains greater than or equal to 10 carbon atoms and preferably C14 to C30.

In general, the sulfur content of the ready-to-use additive liquid hydrocarbon fuels is below 5,000 ppm m / m, preferably below 500 ppm m / m, and more preferably below 50 ppm m / m, or even less than 10 ppm m / m, and advantageously without sulfur, especially for fuels diesel and jet type.

For domestic distillates, the sulfur content is less than 1,000 ppm m / m.

• les carburants essence dont la température d'ébullition est en général comprise entre 20 et 200°C,
• les carburants jet,
• les gazole ou carburants diesel,
• les fiouls domestiques,
• les fiouls lourds dont la température d'ébullition est comprise entre 120 et 500 °C, de préférence 140 et 400 °C

Liquid hydrocarbon fuels can be commercial products, including:

• petrol fuels whose boiling point is in general between 20 and 200 ° C,
• jet fuels,
• diesel or diesel fuels,
• domestic fuel oils,
• heavy fuel oils whose boiling point is between 120 and 500 ° C, preferably 140 and 400 ° C

The present invention also relates to a method for analyzing the fuel or liquid hydrocarbon fuel additive with at least one marker a) which may or may not be contained in a liquid composition as defined above by detection and optionally quantitative analysis of marker (s) a) added to the fuel or liquid hydrocarbon fuel.

• analyse d'un échantillon de composition liquide hydrocarbonée contenant au moins un marqueur a) par une méthode analytique simple, fiable et robuste,
• puis détection d'un ou plusieurs marqueurs a)
• et éventuellement mesure de la concentration de chacun des marqueurs a) détecté au sein du carburant ou combustible liquide hydrocarboné.

The method according to the invention comprises the following steps:

• analyzing a hydrocarbon liquid composition sample containing at least one marker a) by a simple, reliable and robust analytical method,
• then detection of one or more markers a)
• and optionally measuring the concentration of each of the markers a) detected within the hydrocarbon liquid fuel or fuel.

Analytical methods for detecting markers a) implemented in the context of the process according to the invention include, but are not limited to gas or liquid phase chromatography coupled to one or more detectors of markers a) such as electron capture, mass spectrometer and / or flame ionization detector.

Gas chromatography is one of the preferred analytical methods for carrying out the process according to the invention; it makes it possible to separate chemicals according to their interaction with the stationary phase of the chromatography column, either at a constant given temperature or according to a given temperature program. Each chemical compound interacts differently with a given stationary phase in the given temperature condition and therefore has a defined retention time under these conditions. Once determined, the retention time can be used to identify the marker a) while the peak area can be used to determine the marker concentration. Classical gas chromatography (GC) and multi-dimensional gas chromatography-type heart-cutting (GC-GC) coupled to a mass spectrometer (MS) are the preferred analytical methods, the multi-dimensional gas chromatography type "heart-cutting" (GC-GC) which allows better separation is particularly preferred.

We can also mention two-dimensional chromatography (GC * GC or GC2D) a detailed description of which is available in the article entitled " Contribution of two-dimensional gas chromatography. Gas chromatography, GC × GC, two-dimensional chromatography ", available on www.spectrabiology.com / Documents / SA247_26-31.pdf.

MANNER OF REALIZING THE INVENTION

When the analysis method according to the invention uses a method of gas chromatography, the stationary phases used to separate and identify the markers a) according to the invention are in general silicone polymers derived from polysiloxane. This phase is grafted onto the silica column. The polarity of the column can be modified by substituting a phenyl or cyanopropyl group for a methyl group.

There are other much more polar phases based on polyethylene glycol. They are grafted on the silica walls of the column. The columns used are generally capillary columns.

The detectors coupled to the chromatography are preferably mass spectrometry detectors. Mass spectrometry is a very sensitive and specific technique which makes it possible to detect from the ions of the molecule to be assayed of very low content (typically up to 1 ppm m / m), these ions being able to be specific of the markers a) according to the invention.

1. 1) injection dans une 1^ère colonne de chromatographie d'un mélange liquide comprenant une composition hydrocarbonée liquide (par exemple un carburant ou un combustible liquide contenant la composition d'additifs définie plus haut) et un ou plusieurs marqueurs a) ;
2. 2) séparation du ou des marqueurs a) et d'éventuels autres composés contenus dans le mélange ;
3. 3) injection de la fraction dans une 2^nde colonne de chromatographie pour assurer la séparation complète de tous les composés, dont les marqueurs a), puis passage dans un spectromètre de masse permettant l'identification de façon spécifique de chaque composé, (donc de chaque marqueur a)) et leur quantification éventuelle.

The operating conditions of the GC-GC multidimensional chromatography are in general the following:

1. 1) injection into a 1 ^st chromatography column a liquid mixture comprising a liquid hydrocarbon composition (e.g., a fuel or a liquid fuel containing the additive composition defined above) and one or more markers);
2. 2) separation of the marker (s) a) and any other compounds contained in the mixture;
3. 3) injection of the fraction in a 2 ^nd chromatography column to ensure the complete separation of all the compounds, including the markers a), then passage in a mass spectrometer allowing the specific identification of each compound, (therefore each marker a)) and their possible quantification.

The length of the ^1st column is generally between 5 to 60 meters, and is preferably shorter than that of the ^2nd column, which is generally from 10 to 60 meters.

The injector is maintained at a temperature sufficient to ensure the vaporization of all the compounds of the mixture, this temperature is typically between 200 and 350 ° C for hydrocarbon mixtures based on fuel or liquid fuel such as gasoline, kerosene, diesel, fuel oil) and more important in the case of lubricating oils.

The analysis can be carried out at a constant temperature, this temperature being able to vary between 10 ° C. and 300 ° C. The analysis can also be performed using temperature programming. In this case the temperature program will be developed for each type of sample analyzed gasoline, diesel ...

EXAMPLES Example 1

In this example, the GC-GC gas chromatography spectrum of a diesel type commercial fuel EN 590 and that of the same diesel fuel additive with 7 ppm m / m of 4,7-methano-1h-inden-6- are compared. ol, 3a, 4,5,6,7,7a-hexahydro-, acetate ( CAS 5413-60-5 ) (marker a)). For the fuel additive with marker a), the spectrogram shows a retention peak at 23.3 min, which peak does not exist for the fuel which does not contain a marker a).

Using a mass spectrometer coupled to GC-GC, a concentration of 4,7-methano-1h-inden-6-ol, 3a, 4,5,6,7,7a-hexahydro marker is measured. - acetate ( CAS 5413-60-5 ) a) 6.7 ppm m / m (average obtained from 3 measurements, repeatability: 10%)

Example 2

In this example, the GC-GC gas chromatography spectrum of an EN 228 gasoline type commercial fuel is compared with that of the same gasoline fuel additive with variable amounts of butyl acetate ( CAS 123-86-4 ) (marker a)) ranging from 1 to 20 ppm m / m.

For each marker concentration a), the area of the peak is measured; all the data is collected in the table below. Marker concentration a) in the petrol fuel (ppm m / m) Peak area 1 2688 5 18997 10 45446 15 73669 20 99343

From the data in this table, a calibration line (peak area = f (marker concentration a)) is constructed which calculates, for a given peak area, the corresponding marker concentration a)). The corresponding calibration line can be represented by the following equation: $$\begin{array}{cc}\mathrm{Y}=5175.8*\mathrm{x}-4764.3& {\mathrm{R}}^2=0.9979\end{array}$$

The value of the correlation coefficient of the line shows a good linearity over the interval considered.

Example 3

Various commercial EN 590 gas oils with varying amounts of 4,7-methano-1H-inden-6-ol, 3a, 4,5,6,7,7a-hexahydro-, acetate were prepared ( CASE 5413-60-5 ) (marker a)) ranging from 1 to 20 ppm m / m. For each marker concentration a), the peak area is measured and a calibration line is constructed (peak area = f (marker concentration a)) which can be represented by the following equation: $$\begin{array}{cc}\mathrm{Y}=0.00155*\mathrm{x}-0.66999& {\mathrm{R}}^2=0.99895\end{array}$$

A sample of the same commercial gas oil is also prepared to which 8.9 ppm m / m is added. This sample is then stored in a sealed bottle at room temperature for 3 months.

After 3 months of storage, another laboratory again measured by GC / MS the content of the tracer 4,7-methano-1h-inden-6-ol, 3a, 4,5,6,7,7a-hexahydro- acetate ( CAS 5413-60-5 ) in the sample and using the calibration line the marker content a) after 3 months, is equal to 8.65 ppm m / m.

This example shows that the marker incorporated into the fuel remains perfectly detectable over time and also remains perfectly quantifiable.

Example 4

This example relates to a liquid hydrocarbon type gasoline EN 228 containing 2 different markers a) according to the present invention: butyl acetate ( CAS 123-86-4 ) and ethyl caprate ( CAS 110-38-3 ) and a method of analyzing these 2 markers by GC / MS.

The fuel EN228 containing the 2 markers a) is analyzed by conventional gas chromatography equipped with a polar capillary column and coupled to an MS detector (GC / MS).

From the chromatogram and spectrogram data in the table below, the retention time can be assigned to each of the two markers a): Marker a) Retention time butyl acetate ( CAS 123-86-4 ) 7 minutes ethyl caprate ( CAS 110-38-3 ) 27 minutes.

It is noted that the 2 markers are distinguished perfectly from each other by their different retention time but also other molecules contained in the fuel.

Example 5

This example illustrates the use of marker a) according to the invention in a commercial species of the type EN 228. The marker is added via a package of additives improving performance and is analyzed by following the procedure described in Example 4.

The marker, ethyl caprate ( CAS 110-38-3 (marker a)) is incorporated in a commercial performance additive package for gasoline fuel containing a polymeric detergent; a synthetic carrier oil and a mixture of demulsifying agents. The additive package with the resulting marker a) is incorporated into a commercial unleaded petrol fuels EN 228 at a dosage of 500 ppm m / m). By conventional gas chromatography analysis coupled to a mass spectrometer detector (GC / MS) according to the conditions of Example 4, ethyl caprate ( CAS 110-38-3 ) is detected 27 minutes after the injection. All the other components of the essence detectable by the mass spectrometer have passed through the chromatography column either before or after the marker a), and therefore with very different retention times.

Claims (8)

1. Use of at least one liquid composition for marking liquid hydrocarbon-based fuels and combustibles into which it is incorporated, said liquid composition comprising:

   a) at least one marker, chosen from the following aliphatic or cycloaliphatic compounds:

   • tricyclodecenyl isobutyrate (3a,4,5,6,7,7a-hexahydro-4,7-methano-1h-inden-5 (or 6) -yl) (CAS 67634-20-2)

   • tricyclodecenyl propionate (CAS 17511-60-3)

   • cis-3-hexenyl acetate (CAS 3681-71-8)

   • ethyllinalool (CAS 10339-55-6)

   • prenyl acetate (CAS 1191-16-8)

   • ethyl myristate (CAS 124-06-1)

   • para-tert-butylcyclohexyl acetate (CAS 32210-23-4)

   • butyl acetate (CAS 123-86-4)

   • tricyclodecenyl acetate (4,7-methano-1h-inden-6-ol, 3a,4,5,6,7,7a-hexahydro-) (CAS 5413-60-5)

   • ethyl caprate (CAS 110-38-3)

   b) a solvent or a mixture of solvents,

   c) and optionally one or more functional additives for liquid hydrocarbon-based fuels and/or combustibles, chosen from detergents, dispersants, combustion improvers, antifoams, conductivity improvers, anticorrosion additives, lubricant additives, antiwear agents and/or friction modifiers, chelating agents and/or metal sequestrants, de-emulsifiers, colorants, cold-flow improvers, metal passivators, acidity neutralizers, markers other than the markers a), etc.
2. Process for the qualitative detection of at least one marker a) as defined in Claim 1 in a liquid hydrocarbon-based fuel or combustible, comprising the following steps:

   • analysis of a liquid fuel or combustible sample containing at least one marker a) via an analytical method,

   • and then detection of one or more markers a).
3. Detection process according to Claim 2, in which the analytical method is gas chromatography.
4. Detection process according to Claim 3, in which the gas chromatography is multi-dimensional gas chromatography.
5. Detection process according to one of Claims 2 to 4, in which the detection is performed by mass spectrometry.
6. Qualitative and quantitative detection process according to one of Claims 2 to 5, comprising a subsequent step of measuring the concentration of each of the markers a) detected in the liquid hydrocarbon-based fuel or combustible.
7. Detection process according to Claim 6, in which the measurement of the concentration of each of the markers a) is performed by mass spectrometry coupled to gas chromatography.
8. Process for the qualitative and optionally quantitative detection of at least one marker a) according to Claim 6 or 7 by multi-dimensional chromatography coupled to a mass spectrometer, comprising the following steps:

   1) injection into a first chromatography column of a liquid mixture comprising a liquid hydrocarbon-based composition containing one or more markers a);

   2) separation of the marker(s) a) and of any other compounds contained in the mixture;

   3) injection of the fraction into a second chromatography column for the total separation of all the compounds, including the markers a),

   4) and then passage through a mass spectrometer enabling specific identification of each compound (including each marker a)) and optional quantification thereof.